Representative hypnograms of Kcna1-null and wild-type mice. Kcna1-null and wild-type mice were treated with vehicle for 3 d then almorexant for 3 d (100 mg/kg, intraperitoneally). Video-EEG-EMG) data were scored in 10-sec epochs as wake, NREM sleep, or REM sleep for this first 5.5 h of the rest phase, 30 min following injection (Zeitgeber time [ZT] 00:30–06:00). (A) Sleep architecture is shown in representative hypnograms of a wild-type mouse and Kcna1-null mouse on vehicle, compared to (B) the same mice during almorexant treatment. Each hypnogram data point identifies the behavioral state of the mouse at each epoch over time (i.e. during each 10-sec epoch from ZT 00:30–06:00).